Apparatus and method for automatically assembling antifriction bearings

ABSTRACT

An apparatus for automatically assembling antifriction bearings comprising an electric measuring mechanism for measuring the outer diameter of the groove in an inner ring and deriving an electric signal corresponding to the measured size, an electric measuring mechanism for measuring the inner diameter of the groove in an outer ring and deriving an electric signal corresponding to the measured size, an arithmetic unit for comparing the two measured values derived from said measuring mechanisms and deriving a single electric signal corresponding to the difference between the electric signals, a mechanism for selecting rolling elements to be combined with the pair of inner and outer rings by means of said differential electric signal and counting and storing such rolling elements in order of measurements of successive pairs of inner and outer rings, a mechanism for pairing the measured inner and outer rings, and a mechanism for feeding the selected and counted rolling elements into the eccentric clearance between the thus paired inner and outer rings and incorporating a retainer therein, whereby antifriction bearings are automatically assembled by a series of operations of said mechanisms.

United States Patent [72] lnventors Yosio Ono;

Hirosi Nakamura; Takasi lnove; Yosio Horie; Junitiro Matui; Fumito Uono, lwata, Shizuoka, Japan [21] AppLNo. 795,162

[22] Filed Jan.30, 1969 [45] Patented May 4, 1971 [73] Assignee Toyo Bearing Manufacturing Company Limited Osaki-shi, Japan [32] Priority Feb. 3, 1968, Feb. 24, 1968 [3 3] Japan [31] 43/6853 and 43/ 13988 [54] APPARATUS AND METHOD FOR AUTOMATICALLY ASSEMBLING ANTIFRICTION Primary Examiner-Thomas H. Eager Attorney-Hall & Houghton ABSTRACT: An apparatus for automatically assembling antifriction bearings comprising an electric measuring mechanism for measuring the outer diameter of the groove in an inner ring and deriving an electric signal corresponding to the measured size, an electric measuring mechanism for measuring the inner diameter of the groove in an outer ring and deriving an electric signal corresponding to the measured size, an arithmetic unit for comparing the two measured values derived from said measuring mechanisms and deriving a single electric signal corresponding to the difference between the electric signals, a mechanism for selecting rolling elements to be combined with the pair of inner and outer rings by means of said difierential electric signal and counting and storing such rolling elements in order of measurements of successive pairs of inner and outer rings, a mechanism for pairing the measured inner and outer rings, and a mechanism for feeding the selected and counted rolling elements into the eccentric clearance between the thus paired inner and outer rings and incorporating a retainer therein, whereby antifriction bearings are automatically assembled by a series of operations of said mechanisms.

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- SHEET 1 [1F 16 PATENTED HAY 4 I971 CROSS-REFERENCES TO RELATED APPLICATIONS Japanese Pat. application No. 43-6853 dated Feb. 3, 1968. Japanese Utility Model application No. 43-13988 dated Feb. 24, I968.

BACKGROUND OF "IT-IE INVENTION This invention relates to a method of automatically assembling antifriction bearings.

.In the known apparatus for automatically assembling antifriction bearings, the sizes of the mutually cooperative groove diameters of a pair of inner and outer rings to be assembled together are simultaneously computed by a' set of mechanical measuring mechanisms and expressed in terms of a single electric signal, which is then used as a selection indication signal for rolling elements thereby selecting desired rolling elements, the latter being then discharged onto a receiver dish. Such simultaneous mechanical measurement of a pair of inner and outer rings to be assembled together, however, has serious disadvantages. Thus, the measured pair of inner and outer rings have to be paired at once. Therefore, it is only after the paired inner and outer rings have been brought to a regular position and a desired clearance is formed bet veen the paired inner and outer rings that the rolling elements on the receiver dish are fed into said'clearance. Essentially, inner and outer rings .to be paired must of necessity be measured simultaneously, and before the rolling elements on the receiver dish are fed into the clearance the next measurement of inner and outer rings is not allowed, so that much loss of time is caused. This means that the next measurement is not allowed during the time between the beginning and the completion of assembly, thus decreasing the efficiency of assembling work. As a result, the articles are not allowed to stay or stagnate in the intermediate assembling steps, so that a continuous timed operation connected with the individual steps becomes necessary.

If,- therefore, an article stagnates during the assembling work, it is necessary to stop the entire machine and remove the stagnant article.

The present invention has been developed in view of the aforesaid disadvantages of the known apparatus of automatically assembling antifriction bearings.

SUMMARY OF THE INVENTION According to the present invention, the sizes of the mutually cooperative groove diameters of a pair of inner and outer rings to be assembled together are separately measured by indepenerent electricsignals, and a single electric corresponding to the difference between the electric signals is derived by a separately and independently provided arithmetic unit,'said single signal being used as a selection indication signal for rolling elements thereby selecting desired rolling elements. The selected rolling elements are instantly allowed to stay in a temporary storing region successively in order of measurement. Further, the measured inner and outer rings are also allowed to stay in separate temporary storing regions successively in order of measurements. The corresponding inner and outer ring in the separate temporary storing regions are paired or the measured inner and outer rings are instantly paired and such paired rings are allowed to stay in the temporary storing region successively in order of measurement or the measured inner and outer rings are allowed to stay in the separate ternporary storing regions successively in order of measurement and the corresponding inner and outer rings in the separate temporary storing regions are paired together and the thus paired rings are allowed to stay in the temporary storing reand outer rings. Therefore, the use of a suitable memory means will make it possible to measure inner and outerrings at different times. Thus, since the measured inner and outer rings can be reserved separately in the temporary storing regions while memorizing them by the memory means, even if either of the inner or outer rings-stagnate, it is possible to continue the measurement of the inner or outer rings which do not stagnate. Further, because of the provision of the temporary storing regionfor paired articles in accordance with the order of measurement, the assembling of paired articles with rolling elements can be continued until the paired articles in the temporary storing region are used up, even if the measurements of both inner and outer rings are temporarily interrupted. In short, since respective temporary storing regions for inner rings, outer rings and rolling elements in accordance with the order of measurement are provided, individual measurements and assembling operations can be effected in an' overlapping manner.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of the entire apparatus; FIG. 2 is a plan view thereof; FIGS. 3 to 7 are views illustrating an inner-ring groove diameter-measuring mechanism, FIG..3 being a front view,

diameter-measuring mechanism, FIG. 8 being a plan view,

- dent measuring mechanisms and expressed in terms of difgion successively in order of measurement. When the paired FIG. 9-being a section on line 99 of FIG. 8, FIG. 10 being a perspective view on line 10-10 of FIG. 9, FIG. 11 being a section on line 11-11 of FIG. 9;

FIGS. 12 to 14 are views illustrating a clamping mechanism for detectors, FIG. 12 being front view, FIG. 13 being a section on line 13-13 of FIG. 12, FIG. 14 being an enlarged section on line 14-14 of FIG. 12;

FIGS. 15 to 19 are views illustrating an innerand outerring-pairing mechanism, FIG. 15 being a fragmentary perspective view, FIG. 16 being a section on line'l6-16 of FIG. 15, FIG. 17 being a section on line 17-17 of FIG. 15, FIG. 18 being a plan view of a receiver block, FIG. 19 being a perspective view in longitudinal section on line 19-19 of FIG. 18',

FIGS. 20 to 22 illustrate another embodiment of the innerand outer-ring-pairing mechanism, FIG. 20 being a plan view, FIG. 21 being a section on line 21-21 of FIG. 20, FIG. 22 being a section on line 22-22 of FIG. 20;

FIGS. 23 to 32 illustrate means for arranging rolling elements of different sizes according to the instructions and discharging such-elements into the predetermined clearance between paired inner and outer rings, FIG. 23 being a front view in longitudinal section, FIG. 24 being a plan view on line 24-24 of FIG. 23, FIG. 25 being a plan view on line 25-25 of FIG. 23, FIG. 26 being a plan view of a first ratchet part, FIG. 27 being a side elevation thereof, FIG. 28 being a plan view of a rack-pinion part, FIG. 29 being a plan view of a second ratchet part, FIG. 30 being a side elevation thereof, FIG. 31 being a plan view of the rack-pinion type thereof, FIG. 32 illustrates a mechanism for discharging rolling elements contained in a storage sleeve;

FIGS. 33 and 34 illustrate a mechanism for assembling rolling elements in the clearance between paired inner and outer rings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS respective measured values being transmitted to a single arithmetic unit 5.

own weight in chutes '6 and 7 to reach an inner andouter ring pairing mechanism '8, whence the paired rings are delivered to a storage region 9, which is provided in a mechanism 10.

On the other hand, when a pair of rings to be assembled together have been measured as described above, the resulting electric signals are evaluated by said arithmetic unit which, in turn, produces an electricsignal corresponding to the difference between said input electric signals, said output signal serving to select rolling elements to be assembledwith said pair of rings, the thus selected groups of rolling elements being delivered to a storage region.

The ring pairs in the storage region successively reach a rolling element supply position, where such ring pair is given a predetermined eccentric clearance defined between the rings, whereupon the corresponding group of rolling elements in the storage region are discharged to be fed into said eccentric clearance.

Thereafter, any suitable known mechanisms may be employed to complete bearings in a continuous manner.

FIGS. 1-7 illustrate the inner-ring groove diameter-measuring mechanism 3, comprising a main body 11 disposed adjacent the lateral side of the chute 1 and a fixed measuring member 12 having a recess 13 in the upper surface thereof and secured to said main body 11, said chute 1 being connected to said recess. A holder member 14 adapted to be engaged in the inner-ring groove is secured to the bottom of the recess 13 in such a manner that part of the outer peripheral surface thereof projects above the bottom.

A lever 15 is inserted in an opening 16 in the main body 11 and pivotally mounted by a shaft 17. A movable measuring member 18 cooperating with the fixed measuring member 12 is carried on the front end of said lever.

The movable measuring member 18 has an arm 19 projecting from one side thereof. A holder member 20 adapted to be engaged in inner-ring groove is secured to the lower surface of the movable measuring member 18 in such a manner that part of the outer peripheral surface thereof projects below the lower surface, said holder member being vertically aligned with the holder member 14.

The main body 11 has an upper projecting portion 22 formed with a vertical opening 21 (FIG. 5) in which is inserted a detector 23 carrying a front end member 241 constantly pressed against the upper surface 25 of the movable measuring member 18 by means of a spring 26 shown in FIG. 12.

A bracket 27 provided on one side of the upper projecting portion 22 of the main body 11 and above the arm 19 supports a stem 29 for a two-point pulse contact-equipped dial gauge 28. The front end of the stem 29 carries a spindle 30 adapted to be vertically shiftable relative to the stem, the front end 30 of the stem being maintained in contact with the upper surface of the arm 19.

A cylinder 32 secured to an L-shaped support 31 has a piston rod 33 which is in contact with the rear upper portion of the lever 15. A spring 35 is interposed between the lower rear portion of the lever 15 and an L-shaped support 34.

As shown in FIG. 5, the piston rod 33 is always urged downwardly against the force of a spring 36 by an air pressure acting on top .of the piston 43, so that a clearance large enough to receive an inner ring therein is formed between the holder member 14 and 20 of the fixed and movable measuring members 12 and M, respectively.

- In this condition an inner ring is fed into the recess 13 in the I fixed measuring member 12, and upon engagement between the holder member M and the inner-ring groove, the air confined between the cylinder 32 and the upper surface of the piston $3 is discharged to allow the spring 36 to raise the piston 43 and hence the piston rod 33. Therefore, the lever 15 is'turned counterclockwise around the axis of the pin 17 by the spring 35, so that the movable measuring member 18 on the front end thereof is lowered.

The lowering of the movable measuring member 18 causes the holder member 21) to be engaged in the inner-ring groove.

In this connection, it is to be noted that as shown in FIG. 7 the thickness H of the flange 37 of the inner ring is less than the projecting portion D of the holder member 14, so that there exists a clearance with a size D-H between the recess bottom and the flange 37, thus precluding any possibility of the inner ring getting into contact with the bottom surface of the recess.

Thus, it is seen that when the movable measuring member 18 is lowered to cause the holder member 20 to enter the inner-ring groove, the inner ring is held between the holder members 14 and 20 without the flange 37 getting into contact with the lower surface of the movable measuring member 18. The detector 23 in contact with the upper surface 25 of the movable measuring member 18 then detects the displacement of the upper surface 25 of the movable member 18 with the inner ring held between the holder members 14 and 20,

whereby the displacement is derived in terms of an electric signal by the detector 23.

Simultaneously with this measurement of the groove diameter of the inner ring by the detector 23, the dial gauge 28 also measures the diameter. The dial gauge, however, only determines whether the groove diameter is a minus or plus value with respect to a predetermined range of value or is within such range, as will be further described hereinafter.

Upon completion of the measurement of the groove diameter of the inner ring in the manner described above, air is fed to the upper surface of the piston 43 of the cylinder 32, causing the piston rod 33 to lower the lever 15 against the force of the spring 35 until the lower surface of the lever 15 is brought into contact with a stopper 38. As a result, the front end of the lever 15 is turned upwardly around the axis of the shaft 17 to release the holder member 20 of the movable measuring member 18 from its contact with the inner ring, thereby being ready for the measurement of the next inner ring.

In addition, in FIG. 6, the numeral 39 denotes a bearing for the shaft 17; 40, a washer; 41, a clasp; and 42, a keep member for fixing a bearing 39 in position.

With the arrangement as described above, the objects for measurement are held in position only by the two holders 14, 20 of the measuring members 12, 18, and are measured by the detector 23 while they are in a state thus held, and accordingly, the real dimension of diameter of the receiving groove of the inner ring may be measured quite accurately.

Also, because the measuring members 12, 18, the lever 15 and. the detector 23 are fitted on the same body 11, and because the detector 23 is positioned on the axis of the measuring position, the effect of temperature changes may be limited to its minimum.

Moreover, since the bearing is inserted and held in the swinging shaft of lever 15 the lever is prevented from sidewise swings and is enabled to perform repeated measurements in a state of stability, and, thus, as a measuring device, it is highly accurate and usable for a long period of time.

In addition, differences in measurement due to temperature changes could be small, and, at the same time, dimensional divergences in each measurement could also be minor, coupled with the stability of measurement. All these combined make it possible to mitigate the number of times of checking of the standard points due to the passing of time. Consequently, the machine will be required to be stopped less frequently, and this naturally entails an improved work efficiency.

Referring to FIGS. 8-11, the outer-ring groove-measuring mechanism 41 comprises a measuring unit 50 and a positioning unit 51 disposed at both sides of the chute 2.

The arrangement of the measuring unit 50 is as follows.

As shown in FIG. 10, projections 53 and 54 are secured to the upper portion of a main cylinder body 52 on both sides thereof and a shiftable plate 55 is provided between said projections. Rolling bodies 56 and 57 are interposed between the shiftable' plate 55 and the projections 53, 54 so that the plate 55 is shiftable on the main cylinder body 52.

ln 1 16.9, the numeral 58 denotes a guide rod having one end secured to the end surface of the shiftable plate 55 and the other end inserted in a fixing plate 60, with a clasp 61 secured thereto by screw means. The numeral 62 denotes-a springinserted between the shiftable plate and the fixing plate.

'A rolling body 65 is provided between arms 63 and 64 on the fixing plate 60 and adapted to be in contact with the linear portion 67 or recess 68 in the lower surface of a lever 66 so as to urge or release said lever 66.

A support 69, a gate-shaped member 70 and an attaching plate 72 for a fixed measuring member 71 are secured to the shiftable plate 55.

As shown in P16. 11, the support 69 has a recess open to one side, and fixed to the lateral open surface thereof is a cover plate 73 thereby defining a hollow space in the support 69 for insertion of the lever 66 therethrough. Within this hollow space, the lever 66 is supported on a support shaft 74 by means of bearings 75.

A stopper 76 is provided in the lower portion of the support 69 and is opposed to a stop plate 77 which is fixed in position straddling the shiftable plate 55 on the main cylinder body 52, so that when the shiftable plate 55 is advanced, the front end of the stopper 76 will hit against the stop plate 77 thereby stopping the shiftable plate 55.

The numeral 78 denotes a measurement ball projecting above the fixed measuring member 71 and adapted to be engaged in the ball-running groove in the outer ring.

The gate-shaped member 70 straddles the attaching plate 72 and is fixed to the shiftable plate 55. The gate-shaped member 70 has a detector 79 mounted thereon and shiftably guides the lever 66 along the inner surface thereof.

A movable measuring member 80 is provided on the front lower surface of the lever 66 and two balls 81 adapted to be engaged in the ball-running groove in the outer ring are provided on the front upper surface of said movablemcasuring member 80 so as to project therefrom. Y

A spring 82 is interposed as precompressed between the lever 66 and the shiftable plate 59, so that the movable measuring member 80 is constantly urged upwardly.

A stop 83 provided on the stop plate 77 serves to define an upper limit for the turning movement of the lever 66.

The numeral 86 denotes a U-shaped chute connected to the right while maintaining their relative position. Thus the movachute 2 and having openings 85 bored in the lateral wall thereof A bracket 86 provided on one side of the gate-shaped member 70 and above the lever66 fixedly supports the stem 88 of a two-point pulse contact-equipped dial gauge 87. The stem 88 carries a spindle 89 projecting from the lower end thereof and adapted to be vertically shiftable relative to the stem. The spindle 89 is resiliently urged at its front end against the upper surface of the lever 66.

The arrangement of the positioning unit 51 will now be described.

The positioning unit 51 comprises a stop cylinder 90 and a vibrating means 91 for imparting vibrations to outer rings in order to improve the contact between the measuring balls and the ball'running groove in the outer ring prior to the beginning of measurement. The positioning unit is disposed at the other side of the U-shaped chute 84 and opposed to the measuring unit 50.

A stop rod 93 is connected to the piston rod 92 of the stop cylinder 90 and is so positioned as to stop an outer ring so that the axis of the measuring member assembly 71, 80 coincides with axis of said outer ring. The other sidewall of the U-shaped chute is provided with an opening through which a stop rod 93 is advanced. The outer ring rolling on the Ushaped chute will be stopped at a predetermined position by the stop rod 93.

By-mcans of an electric signal issued by an outer-ring-ascertaining switch secured to the lLshaped chute, a magnet valve for actuating a cylinder 52 is caused to operate so that a piston rod 59 and the stop plate 60 are moved to the right as viewed in FIG. 9, whereby those parts which are integral with the shiftable plate 55 through the spring 62, namely the support 69, level 66, movable measuring member 81, fixed measuring member 71 and gate-shaped member 70 are moved to the ble and fixed measuring members and 71 enter the openings 58 in theU-shaped chute 84 and then the outer ring stopped by the stop rod.93, and when the balls 78 and 81 are positioned approximately at the middle of the width of the ball-running groove in the outer ring, the front end of the stopper 76 carried by the support 69 bears against the stop plate 77, whereupon the forward movement of the shiftable plate 55 is stopped.

1n this condition, as the piston rod 59 is further moved to the right, the fixing plate 60 alone is moved while compressing the spring 62 until at last the rolling body 65 becomes engaged in the recess 68, whereupon the lever 66 is turned counterclockwise by the spring 82 around the axis of the shaft 74 while being guided by the inner surface of the gate-shaped member 70, so that the balls 81 enter the outer-ring groove for contact with the ball-running surface and is further raised to raise the outer ring away from the bottom surface of the U- shaped chute 84, and as the balls 81 are still further raised, the ball 78 also enters the ball-running groove in the outer ring and is at lastbrought into contact with the groove bottom, whereupon the upward movement of the lever 66 is finally prevented as the ball 78 thus interferes with such movement.

The advanced position of the piston rod 59 is detected by a switch 94 secured to the lateral surface of the fixing plate 60, as shown in FIG. 8, so that the vibrating means 91 is actuated to cause the conical projection 96 of a plate spring 95 to beat the outer periphery of the outer ring located in the measuring position to impart weak vibration thereto for a predetermined time.

' The purpose of such vibration is to stabilize and perfect the thrusting contact of the balls 78 and 81 with the ball-running groove in the outer ring.

Upon the stoppage of the vibrations, the position of the upper surface 97 of the lever 66 is ascertained by the detector 9 for issuing a corresponding signal.

Simultaneously with the measurement with the detector 79, the spindle 87 of the dial gauge 87 is retracted and the groove diameter is measured also by the dial gauge 87. The measurement with the dial gauge is made in the same way as in the case of the measurement of the groove diameter of the inner ring, the operation thereof being later described in more detail.

The signal issued by the switch 94 actuates a magnet valve for actuating the cylinder to feed air to the front surface of the piston 98 to retract the piston 98 while compressing a spring 99, whereby its contact with the outer periphery of the outer ring which has been raised by the movable measuring member 80 is lost and the obstructionrto the U-shaped chute 84 is removed so as to be ready for the discharge of the outer ring as it rolls out of the U-shaped chute.

After measurement, the cylinder-actuating magnet valve is changed over, so that the piston, piston rod 59 and fixing plate 60 are moved to the left as viewed in FIG. 9. Along with this movement, the rolling member 65 is moved out of the recess 68 in the lever 66 to the straight portion of the lower surface of the lever 66, thereby pivoting the lever 66 clockwise around the axis of the shaft 74. This movement of the lever 66 lowers the movable measuring member 80 to separate the ball 78 of the fixed measuring member 71 from the groove in the outer ring, so that the bottom of the outer periphery of the outer ring comes into contact with the bottom of the chute and the balls 81 of the movable measuring member 80 are separated from the groove in the outer ring.

The above-mentioned operations are effected during the movement of the rolling body 65 from the recess 68 in the 

1. A method of automatically assembling antifriction bearings characterized by measurIng the mutually cooperative groove diameters of a pair of inner and outer rings to be assembled together separately by means of independent measuring mechanisms thereby to express them in terms of different electric signals, computing said different electric signals in a single arithmetic unit provided separately from and independent of said measuring mechanisms thereby to derive a single electric signal corresponding to the difference between the groove diameters of the inner and outer rings, said electric signal being used, to select rolling elements of desired size from a source of such rolling elements classified in advance according to size, the selected rolling elements being instantly allowed to stay in a temporary storing region, said measured inner and outer rings being allowed to stay respectively in separate temporary storing regions and the corresponding inner and outer rings in this temporary storing region being then paired together, the measured inner and outer rings being instantly paired together and then allowed to stay in a temporary storing region, or the measured inner and outer rings being allowed to stay respectively in separate temporary storing regions and then the corresponding inner and outer rings in said separate temporary storing region being paired together and then allowed to stay in a temporary storing region, and feeding the corresponding rolling elements staying in the temporary storing region into the eccentric clearance between the paired inner and outer rings when the latter are brought to a regular position, whereby complete articles are assembled.
 2. An apparatus for automatically assembling antifriction bearings comprising a measuring mechanism (3) for measuring the groove diameter of an inner ring and deriving an electric signal corresponding to the groove diameter of the inner ring, a measuring mechanism (4) for measuring the groove diameter of an outer ring and deriving an electric signal corresponding to the groove diameter of the outer ring, an arithmetic unit (5) fed with said electric signals from said measuring mechanisms as inputs thereof for deriving an electric signal corresponding to the difference between said input electric signals, said derived electric signal being used as a selection indication signal for rolling elements, a mechanism (8) for pairing a set of measured inner and outer rings to be assembled together, which mechanism is capable of discharging those inner and outer rings which are found to be unsuitable for being paired together as a result of the measurement and computation, and means (10) for counting out a required number of rolling elements of required size by means of the selection indication signal from the arithmetic unit, storing them in a temporary storing region and feeding rolling elements into a clearance formed between a set of inner and outer rings to be coupled together as the latter are moved to a predetermined position, wherein temporary storing regions respectively for inner and outer rings are provided between the inner-ring groove diameter-measuring mechanism (3) and inner- and outer-ring-pairing mechanism (8) and between the outer-ring groove diameter-measuring mechanism (4) and inner and outer-ring-pairing mechanism (8) and/or a temporary storing region for paired rings is provided between the inner- and outer-ring-pairing mechanism (8) and means (10).
 3. An apparatus for automatically assembling antifriction bearings as described in claim 2, wherein the inner-ring groove diameter-measuring mechanism comprises a detector and a fixed measuring member disposed above and below a main body, a lever disposed in a central opening in the main body so as to be swingable in a bearing, a movable measuring member corresponding to the fixed measuring member disposed on the front end of said lever, the front end of said detector being resiliently urged locally against the upper surface of the lever, a cylinder and a spring acting on the upper and lower sides at the rear end of said lever, it being so arRanged that at a predetermined time the lever is swung to hold an article to be measured around the outer surface thereof between holder elements provided at the front ends of said two measuring members.
 4. An apparatus for automatically assembling antifriction bearings as described in claim 2, wherein the outer-ring groove diameter-measuring mechanism comprises a shiftable plate disposed on the main body of a cylinder, said shiftable plate carrying an attaching plate for a fixed measuring member, a support for a lever having at its front end a movable measuring member corresponding to the fixed measuring member and adapted to be swingable in a bearing, and a gate-shaped member having a detector mounted thereon, the piston rod of the cylinder being connected to the shiftable plate through a spring, said piston rod having a cam follower substantially secured thereto, the rear end of the lever being shaped in the form of a cam surface resiliently urged against said cam follower by means of a spring, it being so arranged that the movement of the piston rod advances the shiftable plate to bring the two measuring members into an article to be measured, i.e. into the bore of a ring, whereupon the movement of the shiftable plate is forcibly stopped, and thereafter the piston rod alone is moved and the cam follower is moved by the cam surface of the lever, thereby cancelling the swing control on the lever, and thereafter the action of the spring causes the lever to swing to spread the two measuring members in the bore of the ring, this movement of the lever being detected by the detector locally contacted with the upper surface of the lever.
 5. An apparatus for automatically assembling antifriction bearings as described in claim 2, wherein the detector is provided with clamping means therefor which is constructed in such a manner that a detector attaching part is bored with a holding hole for fitting the cylindrical portion of the detector therein, an attaching hole is provided above said holding hole for fitting a stepped bushing therein a space is formed between the lower surface of the stepped bushing and the holding hole, in which space is mounted a ring smaller in diameter than the space and having a bore slightly larger in diameter than the cylindrical portion, and a screw is inserted from the end portion of the detector attaching body toward the center of the holding hole, the front end of said screw bearing against said ring.
 6. An apparatus for automatically assembling antifriction bearings as described in claim 2, wherein the inner- and outer-ring-pairing mechanism is constructed in such a manner that a carrier having on one surface an inner-ring-discharging inclined groove and an inner-ring-supplying groove, on the opposite surface an outer-ring-discharging inclined groove corresponding to said inner-ring-discharging groove and an outer-ring-supplying and paired article passage groove corresponding to said inner-ring-supplying groove, and also having in the upper region of the thickness of the carrier an inner-ring pushing-in opening parallel to a line at right angles with the paired article passage groove and inner-ring-supplying groove, and further having below said opening a receiver block for supporting or releasing outer rings or paired articles within the paired article passage groove, is connected with a two-action three-position stop cylinder by means of which the inner- and outer-ring-supplying grooves, respectively, at both ends of the inner-ring pushing-in opening are brought below inner- and outer-ring-supplying chutes, respectively, or the inner-ring pushing-in opening is brought to a position aligned with a pusher on the lateral side, and at the end of the inner-ring pushing-in operation by the pusher, the receiver block is actuated in association with the operation of the pusher to release the paired article.
 7. An apparatus for automatically assembling antifriction bearings as described in claim 2, wherein the inner- and outer-ring-pairing mechanism iS constructed in such a manner that provided below a fixed body having one surface an inner-ring-supplying groove and on the opposite surface an outer-ring-supplying groove corresponding to said inner-ring-supplying groove and also having in the thickness thereof an inner-ring pushing-in opening communicating with said inner- and outer-ring-supplying grooves is a shiftable body which is slidable in a direction crossing said fixed body, said shiftable body being provided with inner- and outer-ring-dishcarging grooves with the same pitch as the inner- and outer-ring-supplying grooves in the fixed body, said shiftable body being normally aligned with the inner- and outer-ring-supplying grooves, there is provided a pusher on the same axis as the inner-ring pushing-in opening and having its front end disposed facing toward the inner-ring-supplying groove, said pusher being adapted to be advanced and retracted in the inner-ring pushing-in opening at a predetermined time, and there is provided a stopper in the inner- and outer-ring-pairing part adapted to release the paired article in association with the operation of said pusher at the end of the inner-ring pushing-in operation by the pusher.
 8. An automatic bearing-assembling device as defined in claim 2 having different size of ball scoring mechanisms wherein a plurality of storing cylinder members having a hole for receiving a definite number of balls are arranged on the peripheral of an intermittently rotating disc at equal intervals, to said storing cylinder members balls of selected and counted class being supplied in the measured order, whereby several classes of balls of different size are independently pooled.
 9. An automatic bearing-assembling device as defined in claim 2 having different size of ball storing mechanisms wherein a common exhausting outlet for exhausting different size of balls is connected with a disc having a plurality of storing cylinder members through a ball-distributing plate, the upper end of said ball-distributing plate being rotatably fitted to the lower portion of said common exhausting outlet, the lower exhausting outlet of said ball-distributing plate being positioned on the pitch circle of the plurality of storing cylinder members arranged on the disc at equal intervals, whereby the ball-distributing plate is intermittently rotated with respect to the disc by the same pitch as that of the arrangement of the storing cylinder members at the time of selecting and counting balls so as to supply one set of balls in each storing cylinder member.
 10. An automatic bearing-assembling device as defined in claim 2 having different size of ball-storing and exhausting mechanisms wherein the upper end of a ball distributing plate is rotatably fitted to the lower portion of a common exhausting outlet for exhausting different size of balls so as to connect said common exhausting outlet with a hole of said ball-distributing plate, the lower exhausting outlet of said ball-distributing plate being positioned on the pitch circle of the plurality of storing cylinder members arranged on the disc at equal intervals, the upper end of the ball passage in the fixed exhausting plate being positioned at the portion on the lower face of said disc being in alignment with said pitch circle of said storing cylinder members, whereby when said disc is intermittently rotated for bringing a desired storing cylinder onto said fixed exhausting plate, said ball-distributing plate is also intermittently rotated in the same direction with said disc, and when a set of balls selected and counted are supplied into an empty storing cylinder member, only said ball-distributing plate is intermittently rotated in the opposite direction without rotating said disc.
 11. An apparatus for automatically assembling antifriction bearings as described in claim 2, characterized in that dial gauges are provided respectively disposed by the side of the detectors of the inner-ring-measuring part and outer-ring-measuring part for detecting whether tHe groove diameters of inner and outer rings are greater or smaller than or within the ranges of preset sizes, and as a result of the actual measurement and computation of the groove diameters of the inner and outer rings, only in case articles should not be paired such inner and outer rings are discharged and at the same time classified on the basis of the results of the measurement with the respective dial gauges and in accordance with the classification indicated by the dial gauges. 